Method and apparatus for drawing elongated stock continuously

ABSTRACT

A method and apparatus for drawing an elongated stock continuously are disclosed which permit plural types of drawings to be done at a narrower area than in the prior art by a series of automated works and which permits easy adjustment of the distance between a front end position of a plug and an outlet position of a die. A holding member with plural types of dies  18   a  and  18   b  mounted at a central position for reciprocation of an elongated stock is held movably. When the elongated stock is to be moved from one side to the opposite side with the dies holding member as the center, it is passed through an elongated stock passing space, not through the dies, while when the elongated stock is to be moved from the opposite side to the one side with the dies holding member as the center, it is passed through one of the plural dies. The elongated stock is reciprocated plural times between the one side and the opposite side with respect to the dies holding member and the dies holding member is moved at every passage of the elongated stock through a die to change the type of die.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a method and equipment for drawing an elongated stock continuously through different dies.

[0003] 2. Description of the Prior Art

[0004] Heretofore there has been known an elongated stock drawing apparatus for causing the elongated stock to pass through a die into a predetermined diameter. Such a conventional drawing apparatus is shown in FIGS. 13 and 14, which are a front view and a side view, respectively, of the drawing apparatus. The elongated stock drawing apparatus includes, as components shown in FIG. 13, a base 50, dies 52 fixed onto the base 50, a first moving means 56 having a chuck 54 and adapted to reciprocate horizontally on the base 50, a swing means 62 with a rod 60 attached thereto swingably, the rod 60 having a plug 58 at a front end thereof, a hydraulic cylinder 64 for moving the swing means 62 horizontally, the hydraulic cylinder 64 being fixed onto the base 50, and a holder 68 for holding an elongated stock 66 at a predetermined position, the holder 68 being provided above the base 50. The elongated stock 66 is in the shape of a cylinder, one end of which is formed with a flat portion 70 as a flatwise crushed portion as shown in FIG. 15.

[0005] The elongated stock drawing apparatus includes, as components shown in FIG. 14 and in addition to the above components, a lower receptacle 72 disposed at a position lower than the base 50 on one side of the base, an upper receptacle 74 disposed at a position higher than the base 50 on another side of the base, and a transfer means 76 for transferring the elongated stock 66 from the lower receptacle 72 to the upper receptacle 74.

[0006] A description will now be given about a method for drawing the elongated stock 66 with use of the elongated stock drawing apparatus. As shown in FIGS. 13, 14, and 15, a predetermined number (three in FIG. 13) of the elongated stock 66 are put on the holder 68 which is in an inclined state. In this case, the elongated stock 66 are put on the holder 68 in such a manner that the flat portion 70 thereof and a cylindrical opening thereof are positioned up and down, respectively. The swing means 62 has rods 60 whose number corresponds to the number of the elongated stock 66. The swing means 62 adjusts the angle of each rod 60 so that the rods are aligned with the elongated stock 66 on the holder 68. That is, the position of the plug 58 at the front end of each rod 60 is lifted higher than the horizontal position.

[0007] Next, a drive means (not shown) provided at an upper end of the holder 68 is driven to move an elongated stock 66 downward with the cylindrical opening facing down and insert it into a rod 60 from the position of the plug 58 located at the front end of the rod. Thereafter, as shown in FIGS. 13 and 15, the swing means 62 causes the rod 60 to swing into a horizontal position so that a central axis of the rod 60 and the center of the die 52 are aligned with each other. Then, the hydraulic cylinder 64 is actuated to move the elongated stock 66 toward the die 52 until the flat portion 70 of the elongated stock passes through the interior space of the die 52 and projects to the opposite side. At the same time, the first moving means 56 equipped with the chuck 54 moves toward the die 52 and the chuck 54 chucks the flat portion 70 of the elongated stock 66. In this chucked state of the elongated stock 66, the first moving means 56 moves to the side opposite to the die 52. As a result, the elongated stock 66 passes through the die 52 and is thereby drawn into a predetermined diameter. The elongated stock 66 thus drawn is received into the lower receptacle 72 as shown in FIG. 14.

[0008] For drawing the elongated stock 66 into a desired diameter, the stock 66 is subjected to a first drawing into a diameter a little larger than the desired diameter and is then subjected to a second drawing into the desired diameter which is relatively small. As the case may be, the elongated stock 66 is passed a total of three times or more through dies 52 of different diameters.

[0009] Since the length of the elongated stock 66 is large and the lower and upper receptacles 72, 74 are provided sideways of the elongated stock drawing apparatus, the area occupied by the drawing apparatus is large. For this reason, all of the working steps from the beginning to end is carried out using a single elongated stock drawing apparatus. For obtaining an elongated stock 66 of a desired diameter with use of a single elongated stock drawing apparatus, it is necessary that the die 52 and plug 58 used in the first drawing be replaced with smaller ones at the time of shift to the second drawing. This replacing work requires much time and a large number of working steps. The works before and after the replacing work have already been automated, but the attainment of a complete automation throughout all the working steps is obstructed by this replacing work.

[0010] In drawing, the distance X (FIG. 15) between a front-end position of the plug 58 inserted into the die 52 and an outlet position of the die 52 is very important in attaining a high drawing accuracy and it is necessary to adjust the distance X at every replacement of the plug 34. The distance X is checked with the eyes. For checking the distance X with this apparatus, a worker is required to put his or her head into a region (region Y in FIG. 15) on the side opposite to the rod 60 in the die 52 and check the distance X visually. However, the holder 68 is an obstacle when the worker tries to put his or her head into the region Y and thus it is difficult to visually check and adjust the distance X.

SUMMARY OF THE INVENTION

[0011] The present invention has been accomplished in view of the abovementioned points and it is an object of the invention to provide a continuous drawing method and apparatus for an elongated stock which permit plural types of drawings to be carried out in an area narrower than in the prior art by a series of automated works and which permit easy adjustment of the distance between a front-end position of a plug and an outlet position of a die.

[0012] For achieving the above-mentioned object, the continuous drawing method for an elongated stock according to the present invention comprises holding a dies holding member movably, with plural different types of dies being mounted at a central position for reciprocation of the elongated stock, causing the elongated stock to pass through a space of a large diameter, not through the dies, when the elongated stock is to be moved from one side to the opposite side at the position of the dies holding member, while causing the elongated stock to pass through one of the plural dies when the elongated stock is to be moved from the opposite side to the one side at the position of the dies holding member, causing the elongated stock to reciprocate plural times between the one side and the opposite side with the dies holding member therebetween, and moving the dies holding member at every passage of the elongated stock through one of the dies to change the die type from one to another.

[0013] For achieving the foregoing object, the continuous drawing apparatus for an elongated stock according to the present invention comprises a base, a dies holding member movable with respect to the base and with plural different types of dies attached thereto, a chuck means for chucking the elongated stock, a first moving means for,moving the chuck means toward the position of the dies holding member, the first moving means being provided on one side with respect to the dies holding member, a rod to be fitted in the elongated stock, the rod being provided on the side opposite to the first moving means with respect to the dies holding member, and a second moving means for moving the rod toward the first moving means, wherein when the elongated stock is moved to the rod side by the first moving means and is fitted on the rod, the elongated stock is allowed to pass through a space other than the dies at a position lying in the dies holding member, while when the elongated stock fitted on the rod is moved toward the first moving means by the second moving means, the dies holding member is moved so that the elongated stock passes through one of the dies.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014]FIG. 1 is a plan view of an elongated stock drawing apparatus according to an embodiment of the present invention;

[0015]FIG. 2 is a front view of a dies holding member employable in the invention;

[0016]FIG. 3 is a partial front view of FIG. 1;

[0017]FIG. 4 is a configuration diagram of a principal portion in FIG. 1;

[0018]FIG. 5 is a diagram for explaining the operation of a holding/moving means employable in the invention;

[0019]FIG. 6 is a configuration diagram showing in what state an elongated stock passes through the dies holding member;

[0020]FIG. 7 is a configuration diagram showing in what state an elongated stock passes through a die;

[0021]FIG. 8 is a plan view showing other chuck means and pushing/moving means employable in the invention;

[0022]FIG. 9 is a partial plan view showing a state in which a flat portion of the elongated stock is fixed with the chuck means shown in FIG. 8;

[0023]FIG. 10 is a partial sectional view showing a state in which a part of the elongated stock is positioned in an elongated stock inserting space formed in the dies holding member;

[0024]FIG. 11 is a partial sectional view showing a state in which the elongated stock has passed through the elongated stock inserting space in the dies holding member;

[0025]FIG. 12 is a configuration diagram showing a state in which the elongated stock is held by holding rollers;

[0026]FIG. 13 is a front view showing a conventional elongated stock drawing apparatus;

[0027]FIG. 14 is a side view thereof; an

[0028]FIG. 15 is a sectional view of a principal portion in FIG. 13.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

[0029] The present invention will now be described with reference to the drawings. FIG. 1 is a plan view of a continuous elongated stock drawing apparatus embodying the present invention. A support post 12 shown in FIG. 2 is fixed nearly centrally in the longitudinal direction of a base 10 and a dies holding member 14, which is movable vertically, is mounted to the support post 12. An elongated stock passing space 16 of a large diameter is formed in the dies holding member 14 and two different types of dies 18 a and 18 b are mounted to the dies holding member. In this continuous elongated stock drawing apparatus, for example three elongated stocks 20 are to be drawn, so three dies 18 a and three dies 18 b are secured to the holding member 14 horizontally. The elongated stock passing space 16 formed in the holding member 14 is set at a size which permits free passage therethrough of the three elongated stocks 20. The elongated stocks 20 are each in the shape of a cylinder and a flat portion 22 as a flatwise crushed portion is formed at one end of the cylinder.

[0030] As shown in FIGS. 1 and 3, on one side with respect to the support post 12 (the dies holding member 14), a reciprocating member 24 capable of moving in horizontally reciprocating directions is provided on an upper surface of the base 10. Onto the reciprocating member 24 is fixed a pusher means 28 having chucks 26 as chuck means for chucking the elongated stocks. The pusher means 28 causes the chucks 26 to be movable horizontally.

[0031] As shown in FIGS. 1 and 4, on the opposite side with respect to the support post 12, a vertically movable member 30 is provided at a position close to an end of the base 10. A total of two second moving means 32 such as hydraulic cylinders are fixed to the vertically movable member 30 spacedly from each other in the vertical direction. To each of the second moving means 32 is fixed a support member 38 to which are mounted three rods 36 with plugs 34 fixed to respective front ends. The three rods 36 are held horizontally so as to move horizontally in its axial direction upon operation of the second moving means 32. For example, the size of each plug 34 attached to the upper second moving means 32 is set at a size corresponding to each die 18 a, while the size of each plug 34 attached to the lower second moving means 32 is set at a size corresponding to each die 18 b.

[0032] As shown in FIGS. 1 and 3, on the reciprocating member 24 side with respect to the support post 12 (the dies holding member 14), a plurality of holding members 40 for holding the three elongated stocks 30 are provided in a vertically movable manner. The holding members 40 are mounted so that when they have moved upward (when they assume their solid line positions in FIG. 3), central axes of the elongated stocks on the holding members 40 and central axes of the rods 36 are in alignment with each other, while when they have moved downward (when they assume their dotted line positions in FIG. 3), the reciprocating member 24 can move freely on the base 10 without being obstructed by the holding members 40.

[0033] As shown in FIGS. 1 and 5, a holding/moving means 42 is provided for holding and moving three elongated stocks between a position above the base 10 and a position above and sideways of the base. The holding/moving means 42 functions to hold three elongated stocks 20 above and sideways of the base 10, then move up to above the base, and put the three elongated stocks 20 onto the holding members 40.

[0034] The following description is now provided about in what procedure drawing of the elongated stocks 20 is performed using this continuous drawing apparatus. First, the dies holding member 14 is moved to an appropriate position so that elongated stocks 20 pass through the elongated stock passing space 16. Then, the vertically movable member 30 is moved vertically so that rods 36 provided with plugs 34 for the first stage of drawing out of the upper and lower rods 36 shown in FIG. 4 are aligned with the elongated stock passing space 16. The plural holding members 40 are maintained in their upwardly moved state (in their solid line positions in FIG. 3).

[0035] With the holding members 40 thus shifted upward, as shown in FIG. 5, the three elongated stocks 20 are held by the holding/moving means 42 above and sideways of the base 10 and the holding/moving means 42 is moved up to above the base 10, where the three elongated stocks 20 are put onto the holding members 40. With the three elongated stocks 20 thus put on the holding members 40 (FIG. 1), the central axes of the elongated stocks 20 are in alignment with the elongated stock passing space 16 formed in the dies holding member 14 and are aligned with the central axes of the rods 36 provided with plugs 34 for the first stage of drawing. After the three elongated stocks 20 have been put on the holding members 40, the chucks 26 chuck the flat portions 22 of the elongated stocks 20 respectively.

[0036] Thereafter, the reciprocating member 24 moves toward the dies holding member 14 (rightwards in FIG. 1). With this movement of the reciprocating member 24, the front ends in the moving direction of the elongated stocks 20 get into the elongated stock passing space 16 in the dies holding member 14 and then the front-end openings of the elongated stocks 20 are respectively fitted on the plugs 34 fixed to the front ends of the rods 36 (FIGS. 3 and 4). In this fitted state of the front-end openings of the elongated stocks 20 on the plugs 34, the elongated stocks are held by both chucks 26 and plugs 34. Thereafter, the holding members 40 move downward, thereby permitting a further movement of the reciprocating member 24 toward the dies holding member 14.

[0037] The reciprocating member 24 moves maximum toward the dies holding member 14 and thereafter the elongated stocks 20 are further moved toward the rods 36 (for fine adjustment of distance) by the pusher means 28. With the elongated stocks 20 thus moved maximum by the reciprocating member 24 and the pusher means 28, as shown in FIG. 6, the flat portions 22 of the elongated stocks 20 are in an inserted state into the elongated stock passing space 16 (dot-dash line positions of each elongated stock 20 and its flat portion 22) and the flat portion 22 of each elongated stock 20 has not passed the space 16 completely. For allowing the flat portion 22 of each elongated stock 20 to pass completely through the elongated stock passing space 16, as shown in FIG. 6, rollers 44 are disposed near each plug 34, thereby causing the flat portion 22 of each elongated stock 20 to move toward the plug 34 (rightwards in FIG. 6). With the flat portion 22 of each elongated stock 20 thus moved to the plug 34 side (the solid line position of the elongated stock 20 in FIG. 6), the elongated stock 20 passes through the elongated stock passing space 16 completely, whereby it becomes possible for the dies holding member 14 to freely move vertically.

[0038] Subsequently, the dies holding member 14 is moved to move the dies 18 a for performing the first stage of drawing up to the position aligned with the axes of the rods 36. Then, the second moving means 32 is operated, causing the rods 36 with the elongated stocks 20 fitted thereon to advance toward the dies 18 a. When the rods 36 with the elongated stocks 20 fitted thereon have advanced maximum toward the dies 18 a, as shown in FIG. 7, the front ends of the flat portions 22 of the elongated stocks 20 pass the dies 18 a and project up to the side opposite to the rods 36. The chucks 26 chuck the front ends of the flat portions having passed the dies 18 a and then the reciprocating member 24 is moved away from the dies 18 a, whereby the first-stage of drawing for the elongated stocks with the dies 18 a is performed. Before end portions of the elongated stocks 20 pass through the dies 18 a, the holding members 40 are moved up to hold the elongated stocks. Further, the second moving means 32 is operated to move the rods 36 toward the side opposite to the dies 18 a and let the rods return to a predetermined position. The first-stage of drawing is now over.

[0039] Next, for the second-stage of drawing, the dies holding member 14 is moved to place the elongated stock passing space 16 at the position at which the dies 18 a have lain. At the same time, the vertically movable member 30 is moved upward so that the central axes of the rods 36 provided with the plugs 34 for the second-stage of drawing become aligned with the central axes of the elongated stocks 20. Thereafter, the reciprocating member 24 is moved toward the dies holding member 14, allowing the elongated stocks 20 to pass into the elongated stock passing space 16 and be fitted on the rods 36 (plugs 34). At this time, the holding members 40 are moved down and the elongated stocks 20 are fitted on the rods 36 to the maximum extent by both reciprocating member 24 and pusher means 28. Subsequently, the flat portions 22 of the elongated stocks 20 are moved toward the plugs 34 by the rollers 44 serving as retracting means, allowing the elongated stocks 20 to pass completely through the elongated stock passing space 16.

[0040] Next, the dies holding member 14 is moved to locate the dies 18 b at the position at which the elongated stock passing space 16 has lain. Thereafter, the second moving means 32 is operated to move the elongated stocks 20 toward the dies 18 b, allowing the front ends of the flat portions 22 of the elongated stocks to pass through the dies 18 b. Then, the flat portions 22 having passed through the dies 18 b are chucked by the chucks 26 and the reciprocating member 24 is moved away from the dies 18 b. In this way there is performed the second stage of drawing for the elongated stocks by the dies 18 b. Before end portions of the elongated stocks 20 pass through the dies 18 b, the holding members 40 are raised to hold the elongated stocks. Now, the second stage of drawing is over. Thereafter, the elongated stocks 20 are moved to the next process by a conveying means (not shown).

[0041] In the present invention, the elongated stock passing space 16 for free passage therethrough the elongated stocks 20 is formed in the dies holding member 14 and two types of dies 18 a and 18 b are provided. For carrying out the first- or the second-stage of drawing, the elongated stocks 20 are passed through the elongated stock passing space 16 which is an unloaded hole and are moved to a preparatory position for drawing, then the first-stage of dies 18 a or the second-stage of dies 18 b are placed at the position at which the elongated stock passing space 16 has lain, and the elongated stocks 20 are subjected to drawing by the dies 18 a or 18 b. Thus, in case of performing plural types of drawings and when, at a time point other than the drawing process, the elongated stocks 20 are to be moved from one side to the other side of the dies holding member 14 provided with the dies 18 a and 18 b, the elongated stocks 20 are passed through the elongated stock passing space 16 as an unloaded hole and are moved to the preparatory position for drawing, thus permitting plural types of drawings to be carried out continuously with use of a single drawing apparatus. Such a replacing work of replacing the plugs 34 and dies 18 a and 18 b for each type of drawing as in the prior art is no longer needed and a series of automated works can be done. Besides, it is possible to omit works so far needed and thereby shorten the time required for the drawing work.

[0042] Since in the apparatus of the present invention plural stages of drawings for the elongated stocks 20 are carried out while reciprocating the stocks at the same place, the area of the apparatus can be made narrower than in the prior art wherein the elongated stocks 20 are moved sideways every time drawing is performed.

[0043] Before placing the elongated stocks 20 on the apparatus, there is nothing present in an area (area Z in FIGS. 1 and 3) on the side opposite to the rods 36 with respect to the dies 18 a and 18 b. Therefore, a worker can put his or her head in the area Z and see with his or her eyes the distance X between the front end of each of the plugs 34 inserted into the dies 18 a, 18 b and the output of the dies. The worker can adjust the distance while seeing the distance X with the eyes. Consequently, it is possible to draw the elongated stocks 20 with a higher accuracy.

[0044] Although in the above description two types of dies 18 a and 18 b are provided in the dies holding member 14, three or more types of dies may be provided according to the number of drawing stages.

[0045] Although in the above description the elongated stock passing space 16 is formed in the dies holding member 14, only plural dies may be provided in the dies holding member 14 without forming the elongated stock passing space 16 therein. In this case, by moving the dies holding member 14 upward or downward to let the elongated stocks 20 pass through the exterior space.

[0046] When the reciprocating member 24 has moved maximum toward the dies holding member 14 to let the elongated stocks 20 move maximum toward the rods 36 in FIG. 1, the flat portions 22 of the elongated stocks 20 do not completely pass through the elongated stock passing space 16 of the dies holding member 14, as indicated with a dot-dash line in FIG. 6. Therefore, as shown in FIG. 6, the rollers 44 disposed near the plugs 34 are brought into contact with the elongated stocks 20 and are rotated, thereby causing the elongated stocks 20 to pass through the space 16.

[0047] In case of using the rollers 44, however, since oil is adhered to the surfaces of the elongated stocks 20, there has so far been a fear that slipping may occur due to the oil at the time of movement of the rollers in contact with the elongated stocks. Moreover, since the elongated stocks 20 differ in diameter depending on the type thereof, it is necessary to adjust the spacing between the rollers 44, thus requiring the adjusting work. Further, when the rollers 44 come into contact with the surface of each elongated stock 20, the surface of a pipe portion to be used as product of the elongated stock may be damaged.

[0048] In this connection, FIGS. 8 to 11 illustrate another structure which permits the elongated stocks 20 to pass completely through the elongated stock passing space 16 in the dies holding member 14 without using the rollers 44. FIG. 8 illustrates chuck means and pushing/moving means for fixing and holding the flat portions 22 of the elongated stocks 20. The chuck means and pressing/moving means shown in FIG. 8 are used in place of the chucks 26 and the presser means 28. A reciprocating member 80 capable of moving horizontally in reciprocating directions is provided on an upper surface of the base 10 shown in FIG. 1 (omitted in FIG. 8). Plural chucking cylinders 82 are fixed to the reciprocating member 80. An actuating member 84 is attached to a front end of each chucking cylinder 82 and a pair of spaced arms 86 are provided in the actuating member 84. Chucks 88 are fixed to front ends of the paired arms 86 respectively. A chuck means is composed of each chucking cylinder 82, each actuating member 84, a pair of arms 86, and a pair of chucks 88, provided the chuck means is not limited to this construction.

[0049] Each chucking cylinder 82 and each actuating member 84 are in a cylindrical shape and their central axis positions are hollow. The paired arms 86 attached to the actuating member 84 are set so that they can move toward and away from each other. The reciprocating member 80 is formed with wall portions 90. One ends in the moving direction of the wall portions 90 are tapered as tapered surfaces 92 for contact therewith of front-end outer surfaces of the arms 86. By the action of the tapered surfaces with which the front ends of the paired arms 86 are in contact, when the chucking cylinder 82 operates and the actuating members 84 and the pair of arms 86 move away from the chucking cylinder 82 (rightwards in FIG. 8), the pair of arms 86 move toward each other, while when the actuating member 84 and the pair of arms 86 move toward the chucking cylinder 82 (leftwards in FIG. 8), the pair of arms 86 move away from each other.

[0050] When the actuating member 84 for the chucking cylinder 82 is positioned closest to the chucking cylinder 82 (FIG. 8), the pair of chucks 88 do not contact the flat portion 22 of the associated elongated stock 20. Thereafter, when the chucking cylinder 82 operates and the actuating member 84 and the pair of arms 86 move away from the chucking cylinder 82, the pair of arms 86 move toward each other and the pair of chucks 88 attached to the arm 86 come into contact with the flat portion 22 of the elongated stock 20, which flat portion is fixed and held by the pair of chucks 88 (FIG. 9).

[0051] As shown in FIG. 8, pushing/moving cylinders (pushing/moving means) 96 having actuating rods 94 respectively are fixed to the reciprocating member 24. Each pushing/moving cylinder 96 is disposed so that the actuating rod 94 thereof passes through cylindrical interior spaces of the chucking cylinder 82 and the actuating member 84. That is, a central axis of the actuating rod 94, a central axis of the cylindrical space of the chucking cylinder 82, and a central axis of the cylindrical space of the actuating member 84 are aligned with one another. By thus allowing the actuating rod of the pushing/moving cylinder 96 to pass through the interior of the chuck means (by aligning the central axis of the pressing/moving means with that of the chuck means) it is possible to reduce the size of the entire apparatus.

[0052] While the pushing/moving cylinder 96 is not in operation, a front end of the actuating rod 94 is positioned between the pair of arms 86 and is not in contact with the flat portion 22 of the associated elongated stock 20. After the flat portion 22 of the elongated stock 20 is chucked and fixed by the pair of chucks 88 (the state shown in FIG. 9), the reciprocating member 80 moved toward the dies holding member 14 in FIG. 1. By thus moving the reciprocating member 80 toward the dies holding member 14 in FIG. 1, each elongated stock 20 passes through the elongated stock passing space 16 formed in the dies holding member 14 and its front-end opening is fitted on the plug 34 fixed to the front end of the rod 36.

[0053] When the reciprocating member 80 has moved maximum toward the dies holding member 14 in FIG. 1, the greater part of the elongated stock 20 passes through the elongated stock passing space 16 in the dies holding member 14, but the chucks 88 and the pair of arms 92 cannot pass through the space 16. In other words, the flat portion 22 side of the elongated stock 20 does not pass through the space 16 completely (see FIG. 10).

[0054] Thereafter, when the chucking cylinder 82 operates to move the actuating member 84 and the pair of arms 86 toward the chucking cylinder 82, the pair of chucks 88 move away from the flat portion 22 of the elongated stock 20, so that the elongated stock is released from the chucks 88 (FIG. 10). In this state, the elongated stock 20 is held by the plug 34 fixed to the front end of the rod 36. Thereafter, the pushing/moving cylinder 96 is actuated to extend the actuating rod 94. With extension of the actuating rod 94, the front end of the actuating rod comes into contact with a front end of the flat portion 22 of the elongated stock 20. Then, the actuating rod 94 pushes the flat portion 22 of the elongated stock 20 until the flat portion 22 passes through the elongated stock passing space 16 formed in the dies holding member 14. Consequently, the elongated stock 20 can pass through the space 16 (FIG. 11). Subsequently, the pushing/moving cylinder 96 is operated to move the actuating rod 94 back to its original state. Then, the reciprocating member 80 is moved toward the side opposite to the dies holding member 14.

[0055] Thus, when the elongated stock 20 is allowed to pass completely through the elongated stock passing space 16 in the dies holding member 14, the elongated stock 20 is pushed in using the pushing/moving cylinder 96 and the actuating rod 94, thus eliminating the need of contacting the rollers 44 with the surface of the elongated stock 20. Consequently, slipping does not occur during movement of the elongated stock 20 and it is not required to adjust the distance between rollers 44 for each of different diameters of elongated stocks 20, thus making it possible to prevent damage to the surface of the elongated stock 20.

[0056] For preventing damage to the stock surface, such holding rollers 98 as shown in FIG. 12 may be used instead of the holding members 40 used in FIGS. 1 and 3 to hold the elongated stock 20 from below. Although the holding members 40 support the elongated stock 20 from below, the holding rollers 98 support the elongated stock from both right and left sides, and as the elongated stock moves, the holding rollers 98 rotate by virtue of a friction induced by contact thereof with the elongated stock. By forming the contact surface of each holding roller 98 with the elongated stock 20 with use of a material which does not damage the elongated stock, it is possible to prevent the stock surface from being damaged.

[0057] As set forth above, according to the continuous elongated stock drawing method and apparatus, plural types of drawings can be effected by a single apparatus and a series of automated works can be attained. Further, it is possible to omit such a plug and die replacing work for each type of drawing as in the prior art and thereby shorten the time required for the drawing work.

[0058] In the apparatus of the present invention, moreover, since an elongated stock is reciprocated at the same place for plural stages of drawings, so that the area of the apparatus can be made narrower than in the prior art wherein an elongated stock is moved sideways at every stage of drawing.

[0059] In the present invention, since no obstacle is present at the position for visual check of the die-plug distance X, it is possible to visually check the distance X easily. Consequently, it becomes possible to adjust the distance X visually and hence possible to draw the elongated stock with a higher accuracy.

[0060] When an elongated stock is to be passed through the elongated stock passing space formed in the dies holding member, the passage of the elongated stock can be ensured without any fear of slipping, by pushing the front end of the flat portion of the elongated stock with use of the pushing/moving means, thus making it possible to eliminate the need of adjusting the roller-to-roller distance in case of using rollers and hence possible to prevent damage to the surface of the elongated stock. 

What is claimed is:
 1. A method for drawing an elongated stock continuously, comprising: holding a dies holding member movably, with plural different types of dies being mounted at a central position for reciprocation of the elongated stock, causing the elongated stock to pass through a space of a large diameter, not through the dies, when the elongated stock is to be moved from one side to the opposite side at the position of said dies holding member, while causing the elongated stock to pass through one of said plural dies when the elongated stock is to be moved from the opposite side to the one side at the position of said dies holding member, causing the elongated stock to reciprocate plural times between the one side and the opposite side with said dies holding member therebetween, and moving said dies holding member at every passage of the elongated stock through one of said dies to change the dye type from one to another.
 2. The method of claim 1, wherein when said dies holding member is passed through said space of a large diameter, not through the dies, the elongated stock is chucked by a chuck means and is inserted in this chucked state into said space, and after said chuck means releases the chucked state for the elongated stock, the elongated stock is pushed by a pushing/moving means and is allowed to pass through said space.
 3. An apparatus for drawing an elongated stock continuously, comprising: a base; a dies holding member movable with respect to said base and with plural different types of dies attached thereto; a chuck means for chucking the elongated stock; a first moving means for moving said chuck means toward the position of said dies holding member, said first moving means being provided on one side with respect to the dies holding member; a rod to be fitted in the elongated stock, said rod being provided on the side opposite to said first moving means with respect to said dies holding member; and a second moving means for moving said rod toward said first moving means, wherein when the elongated stock is moved to said rod side by said first moving means and is fitted on the rod, the elongated stock is allowed to pass through a space other than said dies at a position lying in said dies holding member, while when the elongated stock fitted on the rod is moved toward said first moving means by said second moving means, said dies holding member is moved so that the elongated stock passes through one of said dies.
 4. The apparatus of claim 3, wherein a pusher means is attached to said first moving means, said chuck means is attached to said pusher means to chuck the elongated stock, then in this chucked state the elongated stock is moved toward said rod by said first moving means and is thereafter further moved toward the rod by said pusher means.
 5. The apparatus of claim 3, wherein a retracting means is provided on said rod side with respect to said dies holding member, and the elongated stock is moved toward the rod by said retracting means.
 6. The apparatus of claim 3, wherein said chuck means and a pushing/moving means for contacting the elongated stock and pushing the elongated stock axially are attached to said first moving means, the elongated stock is moved toward said rod by said first moving means while being chucked by said chuck means, then after the chuck means releases the chucked state for the elongated stock, the elongated stock is moved up to a position on said rod side which position exceeds the movement position of said dies holding member.
 7. The apparatus of claim 6, wherein said pushing/moving means comprises a pushing/moving cylinder and an actuating rod, said chuck means has a chucking cylinder and a cylindrical actuating member, and said actuating rod being disposed so as to pass through a cylindrical space of said chucking cylinder and that of said actuating member.
 8. The apparatus of claim 3, wherein plural types of said second moving means are fixed respectively to vertical moving means adapted to move upward and downward, said rod is fixed to each of said second moving means, and plugs different in diameter are attached respectively to said second moving means which are different from each other. 